JP2000033673A - Laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate having transparency and excellent antistatic characteristics and made heat-sealable as a lid material to a synthetic resin container. SOLUTION: In a laminate wherein a base material layer 2 comprising a stretched film is provided to one surface of a heat sealant layer 3, the heat sealant layer contains at least one of a polyester resin, a polyurethane resin an acrylic resin, a vinyl chloride/vinyl acetate copolymer resin and an ethylene/ acrylic acid copolymer resin and polythiophene represented by formula being an antistatic agent 7. The base material layer 2 is a biaxially stretched polyester film with a thickness of 5-100 μm and the total light transmissivity of the laminate is 80% or more and the haze value thereof is 25% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate and a lid material using the laminate, and more particularly to a laminate having static electricity diffusion and transparency, and semiconductors, IC parts and products thereof as contents.
The present invention relates to a cover material and a bag used for a synthetic resin container for storing a liquid crystal display component, a medical-related article, a food product, and the like.

[0002]

2. Description of the Related Art Conventionally, various kinds of solid or liquid parts, foods and industrial parts have been used for distribution, storage and sales as a package which is housed in a synthetic resin container and whose opening is sealed with a lid. As an assembly part of electric and electronic products,
It is used in the manufacturing process of the product. For example,
As shown in FIGS. 3A and 3B, a content accommodating portion (cavity) 13 is formed in the synthetic resin sheet 12, the electronic component 10 and the like are accommodated in the cavity 13, and then the cavity is covered. Coated with the material 11 and the cavity 13
There is a packaging form in which the peripheral portion is heat-sealed. The synthetic resin sheet 12 forming the cavity 13 is often long, and the package is wound or tape-shaped, and as described above, the cover of the package is used in the assembly line of the electronic product. Is peeled off, the stored electronic components and the like are taken out using an automatic supply device, and are used as a function for component supply such as mounting at a predetermined position. As the material of the synthetic resin sheet, polyvinyl chloride, polypropylene, polystyrene, polyester,
Polycarbonate and the like are all easily charged materials. The lid is a laminate in which a heat sealant layer is formed on a base film, and is heat-sealed to the heat sealant layer and a peripheral portion of a cavity provided in the synthetic resin sheet. The cavity is covered with a lid material, which is a laminate provided with a heat sealant layer, and the periphery thereof is heat-sealed to seal the cavity. In order to prevent the stored electronic components from being deteriorated or destroyed by the static electricity charged on the molded sheet and the lid material, kneading or applying an antistatic agent or conductive fine particles to the heat sealant layer of the lid material. That is being done. The cover material is required to be transparent to the extent that the stored electronic components can be automatically inspected.

[0003]

The above-mentioned synthetic resin sheet, plastic film and the like are easily charged. When these materials are used as a packaging material, the discharge of static electricity charged on the synthetic resin sheet may damage or destroy the electronic components or the like as contents, or affect the driving of the component supply device in the assembly process. There is. Therefore, there is a need for a technique for reducing the generation of static electricity and the amount of charge in a lid or the like made of the synthetic resin sheet and the plastic film. The method of adding an antistatic agent to the heat sealant layer of the laminate is such that when the antistatic agent used is carbon black, metal oxide, or the like, the transparency as a lid material is reduced, and the stored electronic components, etc. May be difficult to see through. When kneading conductive fine particles of a metal oxide into a heat sealant layer or the like, it is necessary to use fine particles having an average particle diameter of 1 μm or less in order not to hinder transparency. However, there is a problem that such fine particles are difficult to disperse, and that an increase in manufacturing cost cannot be avoided. The cover material is required to be transparent to the extent that the stored electronic components can be automatically inspected. The method of applying a surfactant has the disadvantage that not only the sealing property becomes unstable but also the antistatic effect is unstable because it depends on temperature and humidity. The present invention has been made in view of such circumstances, and has as its object to provide a laminate that has transparency and excellent antistatic properties and can be heat-sealed as a lid material for a synthetic resin container. It is.

[0004]

In order to solve the above-mentioned problems, the present invention provides a laminate having a heat-sealant layer provided on one side with a base layer made of a stretched film, wherein the heat-sealant layer is made of polyester. A resin, a polyurethane resin, an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin, a laminate containing at least one of ethylene-acrylic acid copolymer resins and a polythiophene having a structural formula shown below as an antistatic agent,

[0005]

Embedded image

Alternatively, in a laminate in which a base layer made of a stretched film is provided on one surface of a heat sealant layer and an electrostatic diffusion layer is provided on the other surface, the electrostatic diffusion layer is made of a polyester resin, a polyurethane resin or an acrylic resin. A vinyl chloride-vinyl acetate copolymer resin, an ethylene-vinyl acetate copolymer resin, an ethylene-acrylic acid copolymer resin and a laminate containing at least one polythiophene having the structural formula represented by Chemical Formula 1, and The base material layer is
It is a biaxially stretched polyester film having a thickness of 5 to 100 μm, and the laminate has a total light transmittance of 80% or more and a haze value of 25% or less.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The laminate of the present invention will be described in detail. FIG. 1 is a cross-sectional view showing an embodiment of the laminate of the present invention. FIG. 2 is a sectional view showing another embodiment of the laminate of the present invention. Conventionally, the antistatic agent added to the heat sealant layer is, for example, fine particles of carbon black or metal oxide, and has a problem in transparency as a cover material.

The present inventors have conducted intensive studies on an antistatic method for a package made of a synthetic resin sheet or a package made of a molded container and a lid, and as a result, formed a heat sealant layer of a laminate having a heat sealant layer. Adding the polythiophene described in Chemical Formula 1 to the coating solution,
The present inventors have found that a laminate having an antistatic effect can be obtained by providing an electrostatic diffusion layer containing the polythiophene on the inner surface of the heat sealant layer, and have completed the present invention.

The first method is as shown in FIG.
This is a method in which the polythiophene 7 is added to the heat sealant layer 3, and the resin constituting the heat sealant layer 3 includes polyester resin, polyurethane resin, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, ethylene-vinyl acetate copolymer. A coalescing resin, an ethylene-acrylic acid copolymer resin, or the like can be used. The heat sealant layer 3 is formed by applying a coating liquid containing the various resins having heat sealing properties to the base layer 2. The coating liquid includes, for example, the resin, an antistatic agent, a dispersant, a stabilizer, and a diluting liquid. In the present invention, the antistatic agent component is added in an amount of 0.01 to 100 parts by weight as an active ingredient of polythiophene based on 100 parts by weight of the solid content of the resin. The actual formation of the heat sealant layer 3 is selected in consideration of the viscosity, flowability, drying property, etc. of the coating liquid and the physical properties of the base film, but the coating means such as gravure coat, roll coat, air knife coat, etc. This is performed using The thickness of the heat sealant layer 3 is 0.
It is in the range of 1 μm to 60 μm, especially 0.5 μm to 30 μm.
When the thickness of the heat sealant layer 3 is less than 0.1 μm, the heat seal strength is weak, and when the thickness of the heat sealant layer 3 exceeds 30 μm, the sealing time required for heat sealing becomes long, and the base layer 2 is heated by heating the seal. May be damaged.

As shown in FIG. 2A, a second method of forming a laminate according to the present invention is a method for dispersing static electricity containing the polythiophene 7 on the surface of a heat sealant layer 3 laminated on a base material layer 2. A layer 5 is provided. The actual formation of the heat sealant layer 3 includes a resin such as a polyester resin, a polyurethane resin, an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin, an ethylene-vinyl acetate copolymer resin, and an ethylene-acrylic acid copolymer resin. Providing the solution or emulsion in the substrate layer to a thickness of 0.5 to 30 μm,
It is provided with a thickness of 10 to 30 μm by an extruder. Next, a coating liquid containing an antistatic agent is applied to the surface of the heat sealant layer 3 provided on the base layer 2. As the coating method, in the same manner as described above, in consideration of the viscosity of the coating liquid, fluidity, drying property, etc. and the physical properties of the base film, etc., the static electricity is applied by a coating means such as gravure coat, roll coat, air knife coat, etc. The diffusion layer 5 is formed. In this case, the resin forming the electrostatic diffusion layer 5 may be a polyester emulsion, a chlorinated PP emulsion, or the like, or a polyvinylidene chloride emulsion, a polymethacrylate emulsion, a urethane Emulsion, vinyl acetate, poval,
It can be a coating liquid combining one or more of the silane coupling agents. The antistatic agent component to be added to the coating liquid for forming the electrostatic diffusion layer 5 is added as an effective component of polythiophene in an amount of 0.01 to 100 parts by weight based on 100 parts by weight of the solid content of the resin. . The thickness of the electrostatic diffusion layer 5 formed by coating is preferably 0.01 to 30 μm.

As the substrate layer 2 composed of a stretched film to be laminated on the laminate 1 of the present invention, a transparent stretched film formed from a resin such as a polyester film, a polypropylene film, or nylon can be used.
Particularly, a biaxially stretched polyester film having a thickness of 5 to 100 μm is preferable. If the thickness of the base layer is less than 5 μm, dimensional stability when printing on the base material is hindered, and if the thickness of the base layer exceeds 100 μm, it takes a long time for heat sealing, Further, the practicality is lost due to an increase in cost. The surface of the base material layer 2 to be laminated with the heat sealant layer may be subjected to a corona discharge treatment or a primer layer. Further, the other surface may be subjected to a static electricity generation preventing treatment.

As a result of various studies on the antistatic agent to be added to the heat sealant of the laminate of the present invention or to the coating solution for forming the electrostatic diffusion layer, the polythiophene of the following structural formula represented by the above chemical formula 1 was charged. It has been found that excellent results are obtained in terms of prevention properties or transparency as a laminate. That is,

In the present invention, the polythiophene mixed in the heat seal layer or the electrostatic diffusion layer of the laminate is obtained by polymerizing polydialkoxythiophene represented by the formula 1 in the presence of an anion.

[0014]

Embedded image

In the formula, R ₁ and R ₂ independently represent hydrogen or a C _1-4 alkyl group, or a C _1-4 alkylene group which can be substituted simultaneously, preferably a methylene group which can be optionally substituted; It is a dispersion of polythiophene representing an ethylene group, a propylene group, or a 1,2-cyclohexylene group which may be substituted with _1-12 alkyl or phenyl groups. And R ₁ and R ₂ can be formed simultaneously, or typical examples of the formed C _1-4 alkylene group are α-olefins such as ethene, propene, 1-hexene, 1-octene, 1-decene, 1,2-Alkadienes derived from 1-dodecene and 1,2-dibromoalkane, and other 1,2-cyclohexadienes, 1,3-butadiene and 2,3-dimethyl-2,3-butylene and 2,3 -Bentadien. Preferred R ₁
And R ₂ are methylene, ethylene, α-propylene,
Particularly preferred is ethylene.

The polyanion is a polymeric carboxylic acid, for example, polyacrylic acid, polymethacrylic acid or polymaleic acid, and a polymeric sulfonic acid, for example, polystyrene sulfonic acid or polyvinyl sulfonic acid. The polymer carboxylic acid or polymer sulfonic acid can be a copolymer of vinyl carboxylic acid or vinyl sulfonic acid and another polymerizable monomer such as acrylate, methacrylate, or styrene. The molecular weight of the polymeric acid that provides the anion is 1,00
It is in the range of 0 to 2,000,000, preferably 2,000 to 500,000. And it is marketed as a high molecular acid or its alkali salt. As the polyanion to be present when polymerizing the polydialkoxythiophene used in the present invention, a mixture of a free carboxylic acid and / or an alkali salt of the corresponding acid can be used.

In the laminate of the present invention, an intermediate layer 6 may be provided between the base material layer 2 and the heat sealant layer 3, as shown in FIG. 1 (b) or 2 (b). The intermediate layer 6
Can be provided for imparting a necessary barrier property to the laminate or for stabilizing the heat seal (such as buffering properties) when used as a lid. As the intermediate layer 6, specifically, polyester, polyolefin, styrene-butadiene block copolymer, or the like can be used. As a method for forming the resin, a dry lamination method or an extrusion lamination method can be used. The thickness of the intermediate layer 6 is 5 μm to 100 μm.
m is preferred.

Heat sealant layer 3 of laminate 1 of the present invention
Alternatively, the antistatic layer 5 contains the various resins described above and an antistatic agent, and may further contain inorganic fine particles or organic fine particles. The heat sealant layer 3 generally has poor slip, and when the heat sealant layer 3 is placed in a contact and pressurized state with another surface, the heat sealant layer 3 temporarily adheres or adheres to the contact surface, a so-called blocking phenomenon. May occur. In the heat sealant layer of the present invention, the fine particles can be added to prevent blocking. When the fine particles are excessively added, the transparency of the laminate 1 may be impaired. In the present invention, as a result of various studies, the particle size of the added fine particles is 0.01 μm to 100 μm, preferably 0.01 μm to 20 μm.
m and 100 parts by weight of the resin for the heat sealant layer
It has been found that it is preferable that the content be in the range of 1 to 200 parts by weight.

In the heat sealant layer 3 or the electrostatic diffusion layer 5 of the laminate of the present invention, as the inorganic fine particles, SiO 2,
Al ₂ O ₃ , TiO ₂ , Fe ₂ O ₃ , ZnO, SnO ₂ , CeO ₂ , NiO, PbO
, S ₂ CL ₂ , SnCl ₂ , ZnCl ₂ , FeCl ₂ , CaCO ₃ , MgC
O ₃ , B ₂ O ₃ , calcium silicate, aluminum silicate,
Magnesium silicate, calcium silicate, barium silicate, lead silicate, strontium silicate, aluminum hydroxide and the like can be used. Among them, SiO ₂ is preferable. In addition, as the organic fine particles, organic fine particles of acrylic, polyolefin, polystyrene, or polyester can be used.

Further, the laminate of the present invention has the following advantages in terms of transparency.
The total light transmittance is 80% or more and the haze value is 25% or less. When used as a lid of a molded article for storing electronic components and the like, the lid is required to be transparent to the extent that the stored electronic components can be automatically inspected.
If the total light transmittance is less than 80% or the haze value is more than 25%, the contents may not be accurately inspected during the automatic inspection.

[0021]

[Example 1]

<Formation of Electrostatic Diffusion Layer> A coating liquid for forming an electrostatic diffusion layer was applied to a polyester film. Each condition of coating is as follows.・ Polyester film E5100 50 μm (trade name, manufactured by Toyobo Co., Ltd.) One-sided corona treatment ・ Coating liquid Coating liquid for forming an electrostatic diffusion layer The composition of the following six conditions was changed by changing the ratio of the antistatic agent.

[0022]

[Table 1]

* 1) Binder resin polyester emulsion, Finetex ES-850 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.) Solid content 30% * 2) Antistatic agent Solution containing polythiophene as active ingredient Baytron P (BAYER Brand name) Active ingredient 1.3% * 3) Diluent water / IP = 75/25 ｛Abbreviation IP: isopropyl alcohol｝ Percentage of active ingredient in the binder resin, that is, as a dry coating film as an electrostatic diffusion layer Table 2 shows the proportion of the antistatic agent.

[0024]

[Table 2]

<Evaluation of Electrostatic Diffusion Layer> (Evaluation Items)-Total light transmittance Each sample was subjected to [JIS K7105 Plastic optical property test method (1) General optical properties. 5 light transmittance and total light reflectance].・ Haze value For each sample, use [JIS K7105
(2) Special optical characteristics 6.4 Haze (haze value)]. -Surface resistivity The surface resistivity of the surface on which the electrostatic diffusion layer was formed was measured. The surface of the sample left for 24 hours under conditions of 22 ° C. and 40% relative humidity was measured using a resistivity meter MCP-HT260 (trade name, manufactured by Mitsubishi Chemical Corporation). The evaluation results are shown in Table 3.

[0026]

[Table 3]

The laminate on which the static electricity diffusion layer was formed was excellent in transparency. As the antistatic property, an effective component ratio of the antistatic agent to the resin of 100 / 2.5 or more exhibits an effect, and preferably, the ratio is 100 / 5.0 or more. [Example 2]

[0028]

[Table 4]

* 4) Binder resin polyester emulsion, Finetex ES-8
50 (product name, manufactured by Dainippon Ink and Chemicals, Inc.)
Solid content 30% Acrylic emulsion, Neocryl A-655 (product name, manufactured by Zeneca Corporation) Solid content 45% * 5) Antistatic agent Solution containing polythiophene as active ingredient Baytron P (product name, manufactured by company) Active ingredient 1.3% * 6 ) Diluent Water / IP = 75/25 Coating solution Polyester emulsion as resin for binder
Finetex ES-850 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.) Solid content (%) Addition amount (parts by weight) Acrylic emulsion Neocryl A-655 (Zeneca Corporation) as resin for coating solution binder <Electrostatic diffusion layer Evaluation> (Evaluation item) ・ Total light transmittance Each sample was tested according to [JIS K7105 Plastic Optical Property Testing Method (1) General Optical Properties5. 5 light transmittance and total light reflectance].・ Haze value For each sample, use [JIS K7105
(2) Special optical properties: Measured according to 6.4 Haze (haze value)]. -Surface resistivity The surface resistivity of the surface on which the electrostatic diffusion layer was formed was measured. The surface of the sample left for 24 hours under conditions of 22 ° C. and 40% relative humidity was measured using a resistivity meter MCP-HT260 (trade name, manufactured by Mitsubishi Chemical Corporation). (Evaluation results) Heat seal strength A polystyrene sheet having a thickness of 300 μm and the surface of the static electricity diffusion layer of the above example were heat-sealed under the conditions of 150 ° C. and 3 kg / cm ^{2 for} 0.5 seconds, and peeled at a width of 15 mm. The resistance value was used as the heat seal strength. Table 5 shows the results of each evaluation.

[0030]

[Table 5]

In Example 2 and both, extremely good surface resistivity was exhibited, and an antistatic effect was recognized. Both light transmittance and haze were practically acceptable. The heat seal strength is for a polystyrene sheet and has an easy peeling property.

[0032]

According to the present invention, a laminate having excellent antistatic properties can be obtained, and by using the laminate, the packaging of electronic parts and powdery contents which may be destroyed by electric discharge is stabilized. I can do it. Also, because of its excellent transparency, as a package for electronic components, the component is housed in a cavity of a silicate sheet, and as a package sealed with the laminate of the present invention as a lid, an electronic product assembly line In, peel the lid of the package,
Inspection in a package state in a process of taking out the stored parts or the like using an automatic supply device and mounting the parts in a predetermined position can be performed without any trouble.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a laminate of the present invention.

FIG. 2 is a sectional view showing another embodiment of the laminate of the present invention.

FIG. 3 is an explanatory view of a packaging form of electronic parts and the like.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laminated body 2 Base material layer 3 Heat sealant layer 4 Adhesive layer 5 Static electricity diffusion layer 6 Intermediate layer 7 Antistatic agent (polythiophene) 10 Electronic component 11 Lid material 12 Molding sheet 13 Cavity

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C09K 3/16 108 C09K 3/16 108B F term (reference) 3E067 AB01 AB41 AB81 BB14A BB18A BB25A BC07A CA11 CA21 CA24 EA06 EC25 4F100 AK15A AK15C AK15J AK22A AK22C AK22J AK25A AK25C AK41A AK41B AK41C AK51A AK51C AK70A AK70C AK80A AK80C AK80H AL01A AL01C AT00B BA02 BA03 BA07 BA10B BA10C BA13 CA22A CA22C EJ37B EJ38B GB18 JA20B JG03 JG10C JL12A JN01 YY00 YY00B 4H017 AA04 AB01 AB03 AB07 AB10 AB13 AC02 AD06 AE04

Claims (4)

[Claims] 1. A laminate having a base layer made of a stretched film provided on one surface of a heat sealant layer, wherein the heat sealant layer is a polyester resin, a polyurethane resin, an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin, At least one of ethylene-acrylic acid copolymer resin
A laminate comprising a polythiophene having the following structural formula as a seed and an antistatic agent. Embedded image 2. A laminate in which a base layer made of a stretched film is provided on one surface of a heat sealant layer and an electrostatic diffusion layer is provided on the other surface, wherein the electrostatic diffusion layer is made of a polyester resin, a polyurethane resin, or an acrylic resin. A laminate comprising at least one of vinyl chloride-vinyl acetate copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene-acrylic acid copolymer resin, and polythiophene having the structural formula represented by Chemical Formula 1. body. 3. The laminate according to claim 1, wherein the base material layer is a biaxially stretched polyester film having a thickness of 5 to 100 μm. 4. The laminate according to claim 1, wherein the total light transmittance is 80% or more and the haze value is 25% or less.